CALGARY -- Extreme cold warnings have spread to include most of Alberta. Although Calgary and southwestern Alberta aren’t included, this is by technicality only. Environment and Climate Change Canada issues extreme cold warnings when the temperature or wind chill reaches -40 for at least two hours. While Calgary may not reach a wind chill of -40 Sunday night, we could get there during the overnight hours through the first half of the week. Some moderation is expected for the weekend of Feb. 13, but temperatures remain severely below the seasonal average high of 0°C. Greater improvement is likely for the following week when daytime temperatures finally reach the minus mid-single digits.